Pet dogs as sentinels for environmental contamination

Abstract

The presence of environmental contaminants in air, water and food may pose significant health risks to the exposed human population. However, problems associated with assessing chronic exposure to low doses of environmental chemicals, multiple exposure routes, diseases with long latency periods, and non-specific health outcomes make it difficult to conduct the appropriate human epidemiologic studies. It may be useful to complement human epidemiology with animal studies. Animals monitored or evaluated in situ for the appropriate suite of endpoints can provide information about both exposure levels and potential adverse health effects. Animals have served as sentinel indicators for health effects associated with a number of environmental exposures, including pesticides and asbestos. Pet dogs may be particularly valuable sentinels because they share the human environment. In addition, dogs respond to many toxic insults in ways analogous to humans, they have physiologically compressed life spans, and they are free from some important lifestyle risk factors for disease. An example of how pet dogs may be used as sentinels for potential human health hazards involves a study of the genotoxic effects resulting from exposure to a mixture of chemicals from nearby Superfund sites. We conducted a cross-sectional study of exposed dogs (living in the community with the Superfund sites) and controls (living in a nearby community). The pet owners completed a questionnaire, and we collected a blood sample from each dog. The blood samples were analyzed for standard clinical parameters and assays for possible genotoxic effects (peripheral blood lymphocyte micronucleus frequency and lymphocyte subtyping). Pet dogs living near the Superfund sites had a higher micronucleus frequency than control animals, suggesting that the dogs may have been exposed to environmental contaminants from these sites.

Alterations in T-lymphocyte sub-set profiles and cytokine secretion by PBMC of systemic lupus erythematosus patients uponin vitroexposure to organochlorine pesticides

“…This might be a result of higher levels of p,p'-DDE and both α-and β-HCH in their blood. Sub-optimal lymphoproliferative activity (i.e., decreased responses to PHA, ConA, PWM) and modest changes in total white blood cell and lymphocyte levels have been noted in populations exposed to DDT/other OCP (McConnachie and Zahalsky, 1992;Backer, 1995;Vine et al, 2001). Our study also showed that PHA-M stimulation caused a significant increase in CD45RA + CD4 + lymphocyte levels among the PBMC from both SLE patients and healthy controls.…”

Animals as Sentinels for Human Lead Exposure: A Case Report

“…Companion animals, like cats and dogs, often share the immediate environment of people and have access to the same air, water, and food [6,26,27]. Livestock, including cattle, horses, and goats, on the other hand, can have increased exposure to certain environmental toxicants since they live in outdoor environments [22].…”

Survey of spatial distribution of vector-borne disease in neighborhood dogs in southern Brazil

“…Dogs have been indicated as potential public health sentinels because of their close interaction with humans, particularly their owners, while presenting associations with common infectious agents and vectors (Backer et al, 2001;Schmidt, 2009;Schurer et al, 2012). Whereas true sentinels should reveal diseases without harboring them, dogs may become reservoirs for certain diseases such as visceral leishmaniasis (DantasTorres, 2009).…”